Electrochromic devices are today used in widely different applications for enabling control of light transmission. Non-exclusive examples are helmet visors, windows on buildings or automotives, mirrors and goggles. One type of electrochromic devices needs electrical power or charges only during the transition between different transmittance states but keeps the transmittance if the electrical power is disconnected. Such a type is in the present disclosure referred to as a “non-self-erasing electrochromic device”. In one example of such a non-self-erasing electrochromic device, a thin foil of stacked layers is used, incorporating conducting layers, electrochromic layers and an electrolyte layer. In this type of electrochromic device these layers may be provided between two substrate sheets or deposited onto one single substrate, serving as main structural bodies of the electrochromic device. In order to change the transmittance of the device, a voltage is provided between two electron conducting layers. The voltage causes a charging of the electrochromic device, which in turn results in a transmittance change. The level of transmittance is preserved when the voltage is removed. Polymer substrates are useful in many application, e.g. for providing a shape flexibility.
An important process step during manufacturing is the contacting of the electron conducting layers. Since the electrochromic device generally is very thin, so are the electron conducting layers. Contacting from the sides of the electrochromic device becomes practically impossible or at least very difficult to perform in a more or less automated manner. The typical approach for facilitating contacting is to let one substrate sheet with the associated electron conducting layer protrude outside the other substrate sheet. The other substrate sheet and the other electron conducting layer are typically protruding at another portion of the device. Contacting of the electron conducting layers can then be performed at these protruding portions.
In many manufacturing processes of electrochromic devices of today, the production of most of the electrochromic device is performed at the same location. If complex manufacturing processes are used, the production is typically limited to a few sites, which in turn leads to large volume transports of electrochromic devices. If manufacturing is supposed to take place closer to the final site of use or market and since high volume throughput is cost reducing, the manufacturing processes have to be kept simple and of low cost. In that view, it would be beneficial if the production could be divided into different stages. For instance, an electrochromic device sheet could be produced in one stage at a first location. The final assembly of the entire electrochromic device into the final object may then be performed at a later stage and perhaps also at another location. There are, however, several difficulties with such approaches. Since contacting most conveniently is performed in connection with the final assembly, semi-manufactured electrochromic devices with bare electron conducting layers have to be stored and/or transported. The risk for damages in the semi-manufactured electrochromic devices is thus large.
Also, in different applications, electrochromic devices of varying geometrical shapes may be needed. The final shape may even not be known until just before the actual assembly. In such cases, it can be difficult to provide semi-manufactured electrochromic devices with a correct shape in advance, and it would be beneficial if the final shape of the electrochromic device could be cut out from a larger sheet of an electrochromic layered structure. In such cases, the provision of protruding parts appropriate for contacting becomes even more difficult.